You have the following information:
Total surface are of a cube = 253 in²
In order to determine what is the surface area of one face, you take into account that a cube has six faces. Then, the surface are of one face is the total surfaces divided by 6, just as follow:
surface area of one face = 253 in²/6 = 42.16 in²
Hence, the surface are of one face is 42.16 in²